Many privacy-preserving techniques have been proposed for location privacy such as spatial cloaking [1]}, differential privacy [2]}, [3]} or Geo-Indistinguishablity [4]}. These techniques can be applied as the privacy protection mechanism for users' locations in our framework and a pricing model can be derived based on the parameters of these mechanisms, as discussed in Section REF . Therefore, while relevant, these techniques are orthogonal to our work.
